
I happen to have my old Pixel 2 XL still kicking (didn't quite yet want to try it on my daily Pixel 3 just yet) and fired it up.
You go to the website: https://www.google.com/android/beta

No bootloader oem unlock or nothing. Jus opt in and go.
There's not a lot that's noticeably different from Android Pie, but there are a few things if you just look. Here's my quick once over:
So, first up the thing I noticed was the font. I thought I had seen it before on the Android P beta, but checked again against screenshots and no. New font, minor difference.

That's very handy.

Apparently, with Pixel 3 it does the same for the notch.
Kind of a pain, my OCD is going to have a field day with that, but meh ... not a deal breaker. or anything.
For me an almost deal-breaker level annoyance is that to swipe away notifications you can only do it now in one direction: swiping to the right.
Swiping to the left brings up notification options.
For example, with location permissions you can limit access to be only allowed while the app is in use, so while it's hanging out in the background it can't determine that information.
Apparently, there's a built-in feature to do screen recording, but I can't seem to find that option.
I'll keep playing with it. See what I like and provide feedback where I can.
Have you tried it? What do you think?
What will Q be called?